The player takes the role of Django, a vampire hunter, who uses a specialized weapon, the Gun Del Sol, that fires bolts of sunlight at enemies. In order to charge the weapon, the player must actually take the game outside in the daytime (as verified by the light sensor). If your gun runs out of light reserves and there is no sunlight available, you'll have to avoid enemies.

Another unique feature of Boktai is that before a game is started, the player is prompted to set their current time and time zone. The engine can then determine when the sun will rise/set, and will simulate the position of the sun inside the game. This way, the player has an advantage during the daytime because, according to lore, vampires cannot be exposed to sunlight. The game also simulates times of day by putting bird chirp sound effects in the morning, and giving the outdoor environment a soft orange glow around sunset.

Story

In a place not too far from here and now... The End of the World approaches... The Undead appear, breaking the natural cycle of life and death. The evolution of species ceases... and one by one they become extinct. In the age of darkness in which people have forgotten the sun, the "Immortals" -- the beings of the dark -- have appeared and turned San Miguel, the City of the Sun, into a land of death. The dark curse has turned all species into the "undead". "Dark matter" has brought about the "undeadening" of all life. The man who was known as the strongest vampire hunter has fallen, and the people's hopes have been shattered. But one day, a boy who left San Miguel. This boy is Django -- the heir of the solar gun "Gun Del Sol" and the last hope for humanity. In him flows the blood of the greatest vampire hunter of all time. He heads for Istrakan -- the City of Death, to pursue his father's murderer. Can Django avenge his father's death with the use of sunlight as his weapon? Can he stop the undeadening that threatens the lives of all? Can he bring back Our Sun?

Gameplay

Unlike other action RPGs, the combat focuses on stealth. An integral concept is shooting an undead in the back, stunning it then running away or finishing it off. Getting caught by a monster (indicated by a red exclamation point above the head) will reduce the grade received at the end of a stage. The highest grade one can receive is an "S", and the lowest an "C-". A number of other factors also determine the grade received, such as total time taken to complete the level. The only weapon is the gun, but it can use a variety of different lenses which shoot different energies as well as different frames, some of which mimic real guns, with shotgun, automatic, and scatter shots; and more fantasy-based frames with energy spreads, swords, and rotating abilities. Grenades, which attach to the underside of the gun, are a limited supplement. The first kind found merely explodes with a loud sound which alerts all nearby monsters. Later grenades have special effects, such as knocking out all onscreen enemies. There are 2 sun-related varieties, in which one gives the player 4 artificial bars of sunlight for about 30 seconds, while the other gets more powerful depending on the amount of SOL (battery charges, stored into the Solar Stations) gained between uses. Django either shoots grenades straight upward (effect grenades) or forward (attack grenades). Django is accompanied by Otenko, a floating sunflower with a long narrow nose which guides Django through his adventure, revealing the story over time and giving tips on puzzles and fight tactics.

Characters

The Solar Tree

The Solar Tree lets you grow items out of the hollow of its roots with sunlight. Players gain one hollow for each Immortal (excluding Immortals after Carmilla) defeated. The player can grow items by mixing 2 other items. Each item needs a specific amount of SOL to grow and if too much sunlight is used to grow the item, Rotten Nut(s) are obtained. If a player uses a Fast Carrot in the combination, the item grows faster, and if a X2 Carrot is used in the combination, the end result will be more fruit than usual. The Solar Tree grows with collected SOL. When the player gets 600 SOL, the tree is fully grown and you will receive the Sol emblem if you talk to Lita. Upon reaching around 1500 SOL, the Solar Tree will have pink leaves, and the player will obtain a Star Card from Lita, which will allow access to the Astro Battery in all but the Japanese version. Players can see how much SOL is currently collected after finishing the game once, then returning to the Solar Tree and using the new Warp Magic Square.

Sun Bank and Dark Loans

Sun Bank lets you place your collected solar energies inside to raise based on interest rate. You can trade solar energy with another Solar Boy. Sun Bank is only open between 7:00 AM until 12:00 AM. Dark Loans lets you to borrow solar energy with the price of paying what you owe with the interest rate in 3 days. You pay them back by placing the require amount of solar energy in the Sun Bank. If you don't pay them back, Darkness Bugs will haunt you and steal your Solar Energy until they have taken enough to pay off your debt. Dark Loans has a Punish Room that is punishment for those that continueously forget about their debts. When exit your first visit to Dark Loans, you get a Dark Card, which lets you use Dark Loans anywhere except for Undead Traps and Immortal Bosses. Dark Loans is open all day.

Azure Sky Tower

Azure Sky Tower is a bonus level in Boktai that is in the game to challenge skilled players notable for the extreme amount of time required to obtain the dungeon's prize. It is found outside of the right of Ruined Cemetery. The Flame and Frost lenses are required to enter the tower. The tower contains between 12 and 99 random floors with Undead Traps on every (current max floors/3), holding either Swords, Axes, or Krakens. Once the player reach the top floor with the Luna Emblem in their inventory, they will be able to fight the Silvery White Knight. Initially, defeating the Silvery White Knight will net the player the Guardian frame for their Gun Del Sol. Every time the Tower is cleared, regardless of whether or not the Silvery White Knight is defeated, three floors are added to the tower. By building the tower up to the maximum of 99 floors, the player will also obtain the Infinite Battery upon defeating the Silvery White Knight.

Emblem Resonance

When a player first enters the Azure Sky Tower, the Silvery White Knight will randomly give one of four elemental emblems from Earth, Flame, Frost, and Cloud. To get the other 3 emblems you need to trade data with another player that has obtained those Emblems from the Knight. The Emblem a person can trade glows in their inventory. The last three Emblems are obtained elsewhere in the game. To obtain the Dark Emblem, you need to complete the game once. To obtain the Sol Emblem, you need to fully heal the Solar Tree and then talk to Lita. Upon entering the Azure Sky Tower with the six Emblems, the Silvery White Knight will give you the Luna Emblem which lets the player take the final challenge of the tower.

Connection with MegaMan Battle Network 4

In MegaMan Battle Network 4 Red Sun/Blue Moon, Django is part of a funhouse ride featuring vampires. The boss of the vampire robot, whose network contains a story following the adventures of Django fighting the evil vampire Dracky, is ShadeMan.EXE. Django and Otenko later appears in the Undernet as part of a mini-quest to acquire the "S. Sensor" item and activate the PileDriver. He hopes that the PileDriver will delete ShadeMan.EXE, who sleeps in a coffin before Django, regaining strength to revive. The Program Advance 'PileDrvr' is done by selecting the 'GunSol1', 'GunSol2' and 'GunSol3' chips at the same time on the chip selection screen. PileDrvr creates 2 large solar-generators, which each drain 400 HP from enemies between them.

Trivia

One of the available Frames in the game is called Beatmania, a reference to another Konami game series.

Sun Bank and Dark Loans are cards that appear in Metal Gear Acid 2

Another one of the Frames is called Gradius, a reference to a Konami series of the same name.

One dungeon uses the famous Konami Code to reveal a hidden treasure chest.